(-)ESI/CAD MSn Procedure for Sequencing Lignin Oligomers Based on a Study of Synthetic Model Compounds with β-O-4 and 5-5 Linkages
Here, seven synthesized G-lignin oligomer model compounds (ranging in size from dimers to an octamer) with 5-5 and/or β-O-4 linkages, and three synthesized S-lignin model compounds (a dimer, trimer, and tetramer) with β-O-4 linkages, were evaporated and deprotonated using negative-ion mode ESI in a linear quadrupole ion trap/Fourier transform ion cyclotron resonance mass spectrometer. The collision-activated dissociation (CAD) fragmentation patterns (obtained in MS2 and MS3 experiments, respectively) for the negative ions were studied to develop a procedure for sequencing unknown lignin oligomers. On the basis of the observed fragmentation patterns, the measured elemental compositions of the most abundant fragment ions, and quantum chemical calculations, the most important reaction pathways and likely mechanisms were delineated. Many of these reactions occur via charge-remote fragmentation mechanisms. Deprotonated compounds with only β-O-4 linkages, or both 5-5 and β-O-4 linkages, showed major 1,2-eliminations of neutral compounds containing one, two, or three aromatic rings. The most likely mechanisms for these reactions are charge-remote Maccoll and retro-ene eliminations resulting in the cleavage of a β-O-4 linkage. Finally, facile losses of H2O and CH2O were also observed for all deprotonated model compounds, which involve a previously published charge-driven mechanism. Characteristic “ion groups” and “key ions” were identified that, when combined with their CAD products (MS3 experiments), can be used to sequence unknown oligomers.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC000997
- OSTI ID:
- 1470617
- Journal Information:
- Analytical Chemistry, Vol. 89, Issue 24; Related Information: C3Bio partners with Purdue University (lead); Argonne National Laboratory; National Renewable Energy Laboratory; Northeastern University; University of Tennessee; ISSN 0003-2700
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Identification of lignin oligomers in Kraft lignin using ultra-high-performance liquid chromatography/high-resolution multiple-stage tandem mass spectrometry (UHPLC/HRMSn)
|
journal | October 2018 |
Lignin from bark as a resource for aromatics production by hydrothermal liquefaction
|
journal | October 2018 |
Lignin from bark as a resource for aromatics production by hydrothermal liquefaction
|
text | January 2019 |
Similar Records
In Vitro Enzymatic Depolymerization of Lignin with Release of Syringyl, Guaiacyl, and Tricin Units
Initial Products and Reaction Mechanisms for Fast Pyrolysis of Synthetic G‐Lignin Oligomers with β‐O‐4 Linkages via On‐Line Mass Spectrometry and Quantum Chemical Calculations